DL 4959 then DL 5733 at JFK
Jacksonville → New York → Boston
Timetable, New York time
10:09DL 4959 from Jacksonville at the gate
09:50DL 5733 to Boston leaves the gate
23 h 41 apart on the timetable, overnight
DL 5733 leaves 23 h 41 after DL 4959 arrives on the timetable: more than half a day, so not a connection we count.